Optically active J-aggregate formed from water-soluble porphyrin with phenylalanine

Abstract

A water-soluble porphyrin bearing multi-dentate ligands was prepared, and its aggregation behavior in solution under various conditions (temperature, pH, metal ion, chiral compound) was investigated using UV-vis absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy. Upon the addition of Ca 2+ , Ba 2+ , or Sr 2+ to a solution of porphyrin, the porphyrin first forms an H-aggregate and is then transformed to a J-aggregate at 25 °C in buffered aqueous solution (pH 7.4). On the other hand, the porphyrin forms a self-aggregate (H-aggregate) at 25 °C in buffered aqueous solution (pH 6.0), and the H-aggregate does not form the J-aggregate upon the addition of the group II metal ions. The measurement of CD spectra revealed that the H-aggregate that forms right after the addition of Ba 2+ to the porphyrin solution in the presence of D-or L-phenylalanine does not show an induced CD signal, while the J-aggregate formed from the H-aggregate shows induced CD signals in the Soret region.

En Route to a Chiral Melanin: The Dynamic “From-Imprinted-to-Template” Supramolecular Role of Porphyrin Hetero-Aggregates During the Oxidative Polymerization of L-DOPA

“…Recently, a systematic investigation of the effect of porphyrin aggregation on melanin synthesis was undertaken, exploiting the well-known tendency of porphyrins to interact with amino acids (Angelini et al, 2005 ; Uemori et al, 2012 ; Charalambidis et al, 2016 ; Gaeta et al, 2016 ; Rananaware et al, 2016 ; Ryu et al, 2018 ) and polymeric chains (Borovkov et al, 2002a , b ; De Luca et al, 2010 ; Occhiuto et al, 2015 ; Zhao et al, 2015 ; Gaeta et al, 2018 ), with a view to generating new bioinspired functional materials with tailored optical and chiral properties. Water-soluble porphyrins maintain their tendency to aggregate owing to the hydrophobic aromatic macrocycle, whereby binding suitable functional groups to the porphyrin ring may allow to realize self-assembled porphyrin systems in aqueous solution.…”

Emergence of visible light optical properties of L-phenylalanine aggregates

“…Previously reported Phe aggregation models display π-stacking as a large contributor to stable aggregate formation (Gazit, 2002; Mossou et al, 2014; German, Uyaver & Hansmann, 2015; Do, Kincannon & Bowers, 2015). π-stacking has been reported to create optically active aggregates (Kuo, 2011; Handelman et al, 2016) and is responsible for large red-shifts of fluorescence emissions through the formation of J-aggregates (McRae & Kasha, 1958; Higgins & Barbara, 1995; Uemori et al, 2012; Cao et al, 2014), which could overlap with amyloid-bound dye fluorescence. In this work we generated Phe aggregates using previously described methods and analyzed their spectroscopic profiles in order to determine whether they interacted with ThT or formed π-stacking optically active structures.…”

Chiral Recognition of L- and D- Amino Acid by Porphyrin Supramolecular Aggregates

“…Single amino acids have been employed by researchers to transfer chirality to porphyrin’s homo- and hetero-aggregates using either covalent [36,37,38,39,40,41,42,43] or non-covalent approaches [13,44,45]. However, minimal research reports on the chiral properties of the J-aggregates of H 4 TPPS in the presence of amino acids [46,47,48].…”